I had my Optima in my car last year, which maybe gets driven once or twice a week with out a battery tender and had no issues.
David it sounds like you have a drain somewhere. I had this problem years ago when I thought my first Optima was junk, and come to find out the armrest door was broke not letting the light shut off. Simple to check by putting a multimeter in line checking for amp draw.
Ryan,
I've checked for a drain and not finding anything more than what would be normal. I think it was something like .04 amps, but not sure.
I think that at least part of the problem is with my alternator not putting out the voltage it should. When first starting the car it shows 13.8 volts, then after the car is up to full operating temp voltage is down to about 13.0....then when idling at 1000 rpms it will sometimes get as low as 11.9 volts.
Battery charging isn't my main concern, it's the negative impact to the injectors at warm idle that I'm most concerned with. If the car sits at a stoplight idling for more than 15 or 20 seconds it starts going very lean, then fuel trims go real high trying to correct it back to 14.7 or whatever to keep it from stalling, and then when you go to take off from the light it's pig rich and stumbling until you give it enough throttle to clear it out.
We originally thought it was the o2 sensor location (long tubes) causing them to cool off at idle and stop switching, but after digging deeper we discovered the sensors were working fine, so now we suspect the low voltage is fouling up the way the injectors function at idle. Dave has adjusted the tune to quickly trim the fuel both to richen and lean it back out, so it's not that big of an issue. With short term fuel trims turned off, you can barely keeping it running. I also found that if I increase the idle to 1300 rpms by holding the brake and giving it a little gas pedal, everything works fine.
Since swapping to a new alternator didn't really change anything, I had a smaller pulley (2-5/8") made to replace the 3" diameter one that came with the March underdrive set. I expect the smaller pulley to increase voltage about to where it would be now if idling at 1250-1300 rpms. If that doesn't correct the problem, I'll try switching to a low maintance acid filled battery that has more reserve capacity than the Optima. Plan C is a 6G alternator built to make more voltage at idle using the 3" underdrive pulley.
David